Fast Sunday Breath
Fast Sunday breath may not be discussed much by members of The Church of Jesus Christ of Latter-day Saints, but it is something they are aware of and may experience.
On Fast Sunday, traditionally the first Sunday of each month, members of the Church abstain from food and drink for two meals and donate the equivalent cost, or more, to the Church to assist the poor and needy.
Biologically, going without food or water can cause salivary glands to decrease the flow of saliva. A drier mouth can cause a side effect of bad breath.